Thursday, October 29, 2009

Understanding Chocolate Mousse Emulsions

I want to further discuss my chocolate mousse emulsions. Today we are talking science. I promise to keep it mostly understandable. Just keep an open mind and roll with it. I promise that you can successfully make this at home with great results. Remember my Chocolate + Water = Chocolate Mousse posting? The purpose of that blog was to see if I could make a chocolate emulsion product that was 1:1/Chocolate:Water into a rich, decadent mousse like dessert. I did. I noticed there were some inconsistencies between by different recipes. Some were thin, some were too thick. I revisited this to get a better understanding and utilize the microscopes at school to better gauge exactly what kind of emulsions I was making. Knowing this provides insight with how thick/thin based on droplet size, and the droplet size range which tells me how well I mixed it.

When I first delved into making chocolate mousse emulsions, I looked at it more as a recipe of ingredients rather than a very precise processing with the right equipment. The right equipment not meaning some fancy expensive equipment. But rather the right equipment in terms of volume, materials, adequate mixing and temperatures. I will tell you once I get to the procedure....

I did this experiment were I kept the processing (precise making procedures) exactly the same for two very different chocolate mousse emulsions. Let's call them A and B. For A: 4 oz chocolate (I used semi-sweet chocolate chips) + 4 oz water + (sugar + salt to taste.) B:
4 oz chocolate + 4 oz chocolate soy milk. I thought that B would yield a more thicker, stable emulsion considering the soy milk is already an emulsion. Here's the Wiki definition of emulsion with some great diagrams. I define an emulsion to be a homogeneous suspension of two immiscible phases that is stabilized. To get a clear picture on my emulsions, I did some simple polarized light microscopy using the school (Cincy State) science lab microscopes. This picture is from my microscopy investigations. I thought that A would be a simple water in oil emulsion, and B could possibly be a 3 phase emulsion. That is oil droplets inside larger water droplets in the oil (chocolate) continuous phase. It turned out both A and B were 3 phase emulsions!!! I do not have any fancy high-shear mixers or controlled temperature jacketed containers in my kitchen, and yet I got some pretty amazing high-tech results. I am going to tell you know how you can do this in your home kitchen/lab. This chocolate mousse emulsion is amazing because you can make it as simple or as complicated as you would like and account for any dietary restrictions and ready to serve in 15 minutes. The most important thing about making this is having everything ready to go!

  • Scale
  • Thermometer (looking at 32F-212F/0C-100C range)
  • Rubber/Silicone spatula
  • Small saucepan
  • Stainless Steel Bain Marie (available at any restaurant supply stores for cheap)
  • Stick/Immersion blender, preferably with whip balloon attachment
  • Large ice bath for the bain marie
  • Serving cups
  1. Weigh up equal portions of Chocolate and Water (or milk, soy milk, rice milk, etc) into the small sauce pan. Add in sugar and salt as needed to taste.
  2. Slowly heat up over low-medium heat with stirring. Heat until Temperature = 195F/91C. It should appear to be homogeneous dark brown liquid.
  3. Pour/scape all contents into the bain marie and place into ice bath. Immediately start whipping with stick blender/whipper. KEY: the mixer should be significantly submerged into the liquid - if not, use a smaller bain marie/container or scale up your ingredients. Great thorough mixing here and make sure that the container is well surrounded by the ice bath. It should start to thicken about 60F and thicken more as the temperature decreases. Now it is a matter of personal preference on how thick you want it. Take it while cooling & mixing to your desired thickness. It is possible to get too thick - so watch it!
  4. Pour/scape into individual serving cups and put in the fridge to chill for serving. But this is not necessary. I have been know to serve the individual portions immediately in an ice bath. It's usually gone within a blink on an eye.
Try it! You can pretend you're a Chemist in the kitchen, too. Great Cooks are innately Chemists at heart.

-Erin Swing
The Sensitive Epicure


Jenn said...

Great post! I love that you took kitchen to the lab!! I agree, all cooks are chemists at heart, and vice versa :)

Maybe the cocoa solids in the semi-sweet contributed to the good emulsion? I bet if you tried it with white chocolate (which would be lacking in the cocoa solids) your emulsion would be much more degraded compared to with the semi sweet, and would also be expected given its propensity to break emulsion when working with it. It'd also be interesting to look at different % cocoa grades of chocolate and compare (ok the chemist in me needs to stop!)...and of course taste each chocolate mousse as well :)

Erin Swing said...

Hi Jenn! Thanks! Yes, cooking is a series of chemical & physical transformations.

The beauty in making an emulsion with chocolate (regardless of what kind it is: dark, milk, white) is that it is a oil based wax product with a significant amount of lecithin in it which acts as the surfactant/emulisifier. Now all you need to do is heat up oil + emulsifier (any kind of solid, waxy chocolate) with an aqueous phase and mix while cooling down. Hydrophobic waxes are the key for the stability of this colloidal emulsion in the quick crystallization for the structurant.

I like your thinking about the white chocolate. It would be great to do layers...

Yuriy said...

I tried to find an answer to one question. It is may be out of the topic, but... Do you know how to extract cocoa butter from chocolate bar, how to break emulsion. In our country (Russia) it is difficult to find cocoa butter, thus this approach seems appropeiate

Erin Swing said...

Yuriy: Try melting it until homogeneous and sonicating it. Sonicating sometimes helps to break emulsions. Good luck!